Is it possible to configure FreeBSD to login automatically as a specific user?

I've created a user called 'guest' with limited security privileges. I would like to login as this user straight to X to show a video feed. I've configured the guest login to go into fluxbox automatically upon login and show the video feed from my camera automatically, but I cannot get FreeBSD to automatically login the 'guest' user in.

gdm and kdm both support this. You should be able to fairly easily create a fluxbox profile in either of them and configure auto-login. Just check the documentation for whichever one you'd rather use. Not sure if it's doable with the basic Xorg xdm, as I've never tried.